Suffice to say, the fine-mannered doyenne Ms. Astor was not amused. “She was furious! Absolutely furious!” Ms. Kissinger told the jury. To make amends, she said, “letters were sent, flowers were sent, telephone calls were made.”

Twenty years later, all was forgotten.

In 2002, Ms. Kissinger attended Ms. Astor’s 100th birthday party at the home of former Chase Manhattan Bank Chairman David Rockefeller.

Despite having been friends for nearly thirty years–Ms. Astor had even named a dog Henry!–their reunion barely registered with the declining grande dame of New York society. “I don’t believe she recognized me,” Ms. Kissinger said.

Prosecutors are trying to convince jurors that the charitable centenarian had descended into dementia by the time she rewrote her will in 2004, redirecting $60 million in monies previously earmarked for charity to her only son, Anthony Marshall, who now stands accused of conspiracy and grand larceny in an alleged plot to take advantage of his mother’s confused condition and loot her vast fortune.

Testimony so far has also tended to highlight Ms. Astor’s apparent dislike for her son’s spouse, Charlene Marshall, a former preacher’s wife who left her prior husband to run off with Mr. Marshall.

Ms. Kissinger only piled on. She recounted a Christmas party in 2001, when Ms. Astor gave a necklace and earrings to her close friend, Annette de la Renta. As Ms. de la Renta left the room to put them on, Ms. Kissinger recalled, “Brooke turned to me and said, ‘I don’t want Charlene to get them.’”

Taking the stand in a long green dress with gold buttons, Ms. Kissinger brought a stately elegance to a courtroom that was, for the first time in six days of testimony (and counting), packed. Despite the case’s high profile, reporters often had a bench to themselves for much of the past week. But the expected testimony of Ms. Kissinger and, later, Ms. de la Renta brought out new notebooks from the likes of the Los Angeles Times and Women’s Wear Daily.

The buzz was, in fact, audible. Bailiffs cracked down on the reporters’ frequent pow-wows, after the court reporter complained she was having trouble hearing the proceedings.

Following her testimony, Ms. Kissinger immediately headed for the elevator without speaking to reporters.

“Who made your dress? Can you at least tell us that?” hollered one reporter, to no avail.